A number of biological energy transduction processes involve the transport of protons across a biomembrane. The coupling of a protonmotive force, which is a combination of pH gradient and electric field, to ATP synthesis is a basic idea of the chemiosmotic theory of energy transduction. It has been suggested that the path of the proton lies directly through proteins that completely traverse the membrane and that the protons are conducted along a chain of hydrogen bonded residues in much the same way that buckets are passed along a "fire bucket brigade". To help elucidate the details of this mechanism on a molecular level, quantum chemical calculations will be performed to determine the energetics of proton transfers in proteins. As the three-dimensional structure of proteins makes for a wide diversity of different types and geometries of hydrogen bonds that may participate in the chain, various pairs of residues will be considered and for each pair, energetics will be calculated for systematic variations in the hydrogen bond geometry. Calculations will be performed first upon systems composed of small models of each residue to facilitate the application of very accurate techniques including large basis sets and electron correlation. The simplicity of these systems will allow a focusing of attention upon the basics of the proton transfer process without competing effects obscuring the data. The sizes of the models will gradually be enlarged to more appropriate representations of each protein residue to ensure the reliability of the results. Data will be carefully examined for correlations between electronic redistributions and energetics of proton transfer to establish relationships useful for predictions of energetics of large systems from first principles. The large body of reliable and systematic data obtained from these studies will be used to determine the structural requirements and kinetics of an efficient proton conduit. Information dealing with the effects of environment (e.g., pH, hydrophilicity, temperature) upon the process will also be forthcoming from the data.